The conventional drawer lock is used to lock the drawer so as to protect the important goods or documents in the drawer. The thief does not damage the key plug of the lock directly, and instead, uses a strong plate-like member to directly push the curved portion of the key plug which is pushed by the plate-like member and retracted so as to open the drawer.
FIG. 1 shows the drawer lock 10 disclosed in U.S. Pat. No. 5,657,652 and generally comprises a main bolt 20 and a deadlocking bolt 30. A spring 201 is located between the inner end of the housing of the lock 10 and the main bolt 20. The main bolt 20 has a stepped face 202 and the deadlocking bolt 30 is connected with a locking arm 40 which has a hole 401 through which a pin 301 extends to connect the deadlocking bolt 30 and the locking arm 40. A resilient member 302 is located between the deadlocking bolt 30 and the locking arm 40 and another resilient member 303 is locked between the deadlocking bolt 30 and the inner end of the housing. The locking arm 40 contacts the main bolt 20 when the main bolt 20 is forced to retract. A cam 50 is located in the housing and co-rotatably connected to the key plug. The cam 50 has a protrusion 501 and a push portion 502, wherein the protrusion 501 is located to be displaceable into contact with the stepped face 202 and the push portion 502 is located to displace the locking arm 40 responsive to rotation of the cam 50. As shown in FIG. 2, when the cam 50 rotates in one direction, the push portion 502 pushes the locking arm 40 to be separated from the main bolt 20. The protrusion 501 contacts the stepped face 202 and the main bolt 20 moves toward the spring 201 to unlock the lock.
The user usually pushes the drawer slightly and the main bolt 20 and the deadlocking bolt 30 are not engaged in the recess of the cabinet when the drawer is not opened. However, the main bolt 20 and the deadlocking bolt 30 protrude from the housing of the lock 10 by the spring 201 and the resilient member 303 so that the main bolt 20 and the deadlocking bolt 30 are easily pushed to compress the spring 201 and the resilient member 303 and inserted into the recess of the cabinet. The user has to rotate the key plug (unlock the lock) to open the drawer again. This is not convenient for the user. Besides, if the key is put in the drawer and the drawer is unintentionally locked, the user has to call a locksmith, otherwise, the drawer lock has to be damaged to open the drawer. Extra expense is required.
The present invention intends to provide a drawer lock which improves the shortcomings of the conventional drawer lock.